Muffle furnace



Aug. 7, H923. 11,464,248

C. F. GEIGER MUFFLE FURNACE Filed May 31. 1922,

INVENTOR ATTORNEY? lf atented' u I, 1923.

PATENT OFFICE.

CHARLES 1F. GEIGEB, 0F PERTH AMJBOY, NEW JERSEY, ASSIGNOB TO THE CAR-IEBORUNDUM COMPANY, @F NIAGARA PENNSYLVANIA. I

EUFFLE Application flleu May 31,

To all whome't may com-em:

Be it known that I, Cinema GEIGEIR, a citizen of the United States,residing at Perth Amboy, county of Middlesex, State of New Jersey, haveinvented a new and useful Improvement in Muflie Furnaces, of which thefollowing is a full, clear, and exact description, reference being hadto the accompanying drawings, forming part of this specification, inwhich Figure l is a partial horizontal section on the line I-I ofvrigure 2;

Figure 2 is a transverse vertical section; and

Figures 3 and 4 are perspective views of two forms of tile which Iprefer to employ.

My invention relates to muflie furnaces wherein the material to beheated is out of contact with the combustion gases and particularly to anew and improved construction for the roof and side walls of the mufiiechamber.

I will now describe'my invention as applied 'to'a me furnace, such asused in tit \ ename of iron or steel or burning terra outta, it beingunderstood that it may be appliedto any mufiie furnace. In such afurnace, there is an internal closed chamber or -rne havingsubstantially vertical side walls and an arched roof-with spaces beneaththe fioorg around the sides, and above the roof of the muflie, for thecirculation of combustion gases, the mufiie being surrounded by anenclosing structure containing the combustionchambers. The combustionchambers are ordinarily beneath or adjacent to the floor of the mufile,"and the gases after bein discharged underneath the floor are led up ilmfines at the sides of the furnace between the outside and side walls,and thence along the roof between the outside and inside arches and thendischarged. In an cases, thegases are closed ofifrom the mue chamber,since in this class of work it is necessary to keep the gases away fromthe articles bein treated.

In the mu Iii furnaces, the wall of the mufile acts to isolate theatmosphere inside the mufie chamber from the combustion gases, and atthe same time conduct heat from the gases into the chamber. It isdesirable that the mufile walls should be thin, so that the greatestamount of heat may be transmitted,

but it is diflicult to obtain this object while FALLS, NEW YORK,CORPORATION OF FURNACE.

1922. Serial No. 564,868.

retaining the proper structural strength. The roof of the mufile hasordinarily been made of slabs of a considerable thickness,

necessary to give proper strength and bear- 1long at the edges andprovide proper sta- 1 lty.

In accordance with my invention, the side walls and arches of the muffleare formed of hollow tile, this being particularly important in the roofarch construction.

In the drawings, 2 represents the general masonry structure of a mufliefurnace containing a'muifle of which the s de walls are formed of hollowtiles 3, and the roof arch is also formed of hollow tiles 4:. The endWalls of these hollow tiles may be and preferably are provided withalternate grcjections and recesses 5 and 6, so that one row of tileswill interlock with the adjacent rows and give intersupporting of therows. This, however, may or may not be used as desired. The fire boxesindicated at 7 are preferably staggered on opposite sides of the mufiechamber so that the gases of combustion from one side will pass throughtheir flues around the mufie in a direction opposite to those in thefire box on the opposite side. This compensating arrangement givesgreater uniformity of temperature in' the mufle because the hottestgases from one part of the furnace will heat a section next adjacent tothe .part where the cooler gases from the opposite fire boxes pass.

In the form shown, the gases leaving the tire box divide, a portion ofthem passing through the flues 8 underneath the fioor of the muflie andup the side flue 9 to the exit flue 10, while the other portion passesup through the side flues 11, thence throu h the roof arch flues and tothe other exit ue at 12. The exit flues are preferably provided withdampers 13, so that the flow of gases in either direction may be bettercontrolled.

b Instead of dividing the gases at the fire ox boxup the side flue, overthe top of the arch, down the other side fine and then back through thebottom flue to an exit flue adjacent the firebox.

The tiles are preferably made of bonded A 105 siliconcarbide, as this'v'es greater structural strength and high vt ermal conductivity at hightemperatures; For example, if I use a tile of a cross section of sixinches in- 30 out departing from my invention.

' side dimensions, withthe side walls of the tile one-half inchthick, Ican obtain all the stability of a wall or arch six inches thick,

. and at the same time, obtain the conductivity hollow tiles, and thencebeing carried across chamber.

and under the roof of the mufile in the form of an arch. This will givea larger radiating surface from the tile into the muflie, since' theroof tiles will-be in the muflie Again, instead of the self-supportingarches of square or rectangular tiles, as shown, I may employcylindrical tiles, or tiles of other cross sectional shape, each archbeing a self-supporting unit. These arches may be laid close together,whether interlocked or not, or may be spaced apart, if desired.

The furnace may be used for many pur-' poses, and other changes may bemade with- I claim:

1. In a, muffle furnace, a muflie having in its roof hollow tilesforming a self-supporting arch and arranged to form a flue for productsof combustion, said tiles being of uniform thickness throughout theirlength and joined together end-to-end without overlapping portions.

In amuflie furnace, a mufiie having it roof portion formed of hollowtiles forming a self-supporting arch comprising a plurality of flues,and means for directing combustion gases through the fiues formed bysaid tiles, said tiles being of uniform'thickness throughout theirlength' and the tiles in each flue being joined together endtoendwithout overlapping portions.

3. In a muflie furnace, a mufile having its roof portion formed ofhollow tiles forming a self-supporting arch and constructed and arrangedto form a plurality ofinterlocking fiues, and means for directingcombustion tiles.

side walls formed of superimposed hollow tiles forming a flue forcombustion gases, said tiles being of uniform thickness throughout theirlength and joined to gether end-to-end without overlapping portions.

5. In a mufiie furnace, a mufile having its side walls and roofcontaining combustion flues formed of hollow tiles, the tiles of theroof forming a self-supporting arch, said tiles being of uniformthickness throughout their length and the tiles in each flue beingjoined together end-to-end without overlappin r port1ons.

6. A mu e furnace having its side walls formed of hollow tilesconstructed and arranged to form a plurality of interlocking flues, andmeans for directing combustion gases through the flues formed of saidtiles.

7. A mufile furnace having the mufile with its side walls and roofformed of hollow tiles forming fines for combustion gases, the "rows oftiles interlocking with each other.

In testimony whereof I have hereunto set my hand.

- CHARLES F. GEIGER.

gases through the flues formed by said 4. In a mufile furnace, a mufllehavingits;

